This video about "cymatic" describe exactly some aspects of what i spoke about...
Hans Jenny the cymatic creator was a disciple of the Goethe phenomenological approach in science and pupil of Rudolf Steiner...
https://www.youtube.com/watch?v=Q3oItpVa9fs
No need to have "sands" or water....Timbre perception play the role of sand....
The rythmic changes in the controlled pressure zones of a room
using Helmholtz method to do it mechanically induce in my listening experiments the visualization of the TRADE-OFF between localisation and width of a "point-like" object or of the sounding resonant body of the violin for example and the spreaded out dynamical localisation of the "timbre" microdynamic related to this resonant body which is also a sound source with a variable dimension and location in the room which we can modify at will with the right acoustic control...
Using material passive treatment in acoustic and active mechanical control will optimize this TRADE-OFF, between source width (ASW) and listener envelopment ( LEV) which is for me at the heart of small room acousttic...
Yes it is a bit more complicated than looking only for a "stereo" image and localization left/right ....
Most people dont understand acoustic....I struggle with it myself but i become able to know what it is about even if i dont undertand it all... By the way understanding for me is " seeing" first not applying a mathenatical formula only....
And even some educated one confuse timbre and spectrum.....
We must meditate about this fact: no recording is able record the perfect original playing musical event, and no small room is able to reproduct it but only to recreate it in his own acoustic translation satisfyingly or less than so, depending of the mastery of room passive treatment and active mechanical control....
The acoustic of small room is NOT the acoustic of big hall or theater.... The goal and tools here are different....
To this day all audio business and hobby completely underestimated acoustic in favor of progress in electronical design...
Audiophiles then instead of focusing on acoustic spend their money in an empty chase of their tail very costly sometimes...
No electronical design progress in gear can replace acoustic....The reverse also is true for sure...But the audio engineering field was already mature decades ago.... Acoustic of small room is not a mature enterprise in the audio world...Only a dedicated business of those few who knows it ... I never read an article about what interested me in acoustic mechanical control of small room in ANY audio review...NONE...
The reason is simple, most people dont understand Helmholtz mechanical method...
Acoustic sellers sell costly Helmholtz generator to replace bass traps for example...It is a very limited way to understand Helmholtz generator and use them like i use my grid of more than 40 like a "silent orchstra" or like the silent big pipes linked to an organ in a chuch...To absorb some sounds and diffuse others...
And any way the subject matter cannot interest someone who dont own a dedicated room....
A grid of Helmholtz genrators cannot be used in a small living room...